Treatment of hydrocarbon oils



Sept. 16, 1958 E. PUDDINGTON ETAL 2,852,454

TREATMENT OF HYDROCARBON OILS Filed July 19, 1956 flu) ATTORNEYS INVENTORS United States Patent TREATMENT OF HYDROCARBON OILS Ira Edwin Puddington and Aurelio Frederick Sirianni,

Ottawa, Ontario, Canada, assignors to National Research Council, Ottawa, Ontario, Canada, a body corporate of Canada Application July 19, 1956, Serial No. 598,855

8 Claims. (Cl. 204-136) The present invention relates to a process and apparatus for the continual treatment of hydrocarbon oils, such as lubricating oils, transformer oils, fuel oils and heat transfer oils, in order to reduce or prevent deterioration of such oils during use.

Hydrocarbon oils of the type mentioned tend continually to deteriorate and this results in discoloration and sludge formation, as well as in the formation of acid reacting products. Such deterioration is evidently caused by oxidation reactions and also by thermal decomposition. In the case of lubricating oils, the weight of the research into the causes of deterioration of these oils indicates that the main cause is oxidation and that thermal decomposition, at least at normal engine lubricating temperatures, is a comparatively minor contributory factor. However, the results of the deterioration of hydrocarbon oils are well known, especially by motorists who find it necessary, as a consequence, to effect periodic oil changes with the attendant extra trouble and expense. Also, research has indicated that engine deterioration and wear are traceable to the deterioration of the lubrieating oils during use.

It is the object of the present invention to provide for a simple and inexpensive continual treatment for hydrocarbon oils to reduce or remove their tendency to deteriorate during storage or use. As indicated, the tendency of hydrocarbon oils to deteriorate is a continual one and consequently a continuous process is required to combat it. This is an important factor to be borne in mind since it is radically different in this respect from other types of oil treatment, such as refining. In the latter instance, the oil is given some treatment to effect the desired improvement and thereafter the oil is considered as so improved and in need of no repetition of the treatment. For example, oils are treated to remove wax and asphalt but, once these substances are removed, no repetition of treatment is necessary as there will be no further formation or addition of such substances to warrant further treatment. In such cases, the treatment will usually consist of a continuous proeessn'n which the untreated oil is passed through the treating apparatus in a continuous stream and then removed to 'be employed as required.

In contradistinction, according to the present invention, a continual treatment *of substantially the same batch of oil is effected so that its tendency to deteriorate is continually combatted so as to prevent discoloration and sludge formation from taking place, as well as to prevent such oil from assuming an acid reaction.

According to the invention it was found that when hydrocarbon oils of the type mentioned are maintained in continual contact with even only a relatively small element, the essential components of which are a solid sodium-solder alloy and solid metallic calcium in electrical contact with said sodium-solder alloy, preferablywith movement of the oil over such element, such as by recycling the oil through a treating zone containing 2,852,454 Patented Sept. 16, 1958 "ice the element so as to ensure thorough contact of the sodium-solder alloy and calcium surfaces with the oil, the normal tendency of such oils to deteriorate is reduced to a very substantial degree.

The invention is particularly applicable to oils while in use and therefore particularly subjectto deterioration. An application of the invention which has been found particularly effective is to oil circulating in the oil lubricating circuit of an internal combustion engine. In such case, the continual treatment according to the invention can, for example, be carried out by positioning the sodium-solder alloy and calcium containing element in the circuit so that the circulating oil will continually contact :the sodium-solder alloy and calcium surfaces. Preferably the element according to the invention is placed in the oil circuit in such a manner that it can readily be changed. For example, the element can be secured to .a supporting member which is capable of being in or adjacent to the oil circuit so that the sodium-solder alloy and calcium surfaces will contact the oil in the circuit.

It has, for example, been found particularly expedient to secure the sodium-solder alloy and calcium in electrical contact with each other to the inner end of a crankcase drain plug. Also, the element according to the invention may be incorporated in a filter inserted in the oil circuit.

Preferably the sodium-solder alloy and calcium employed in the element according to the invention are not in particulate form but rather in the form of a solid mass so as to prevent particles of the treating materials from being entrained by the oil leaving the treating zone. It was found that in use an occasional-small particle may come away from the solid mass of treating metals but this can be tolerated.

It is of course also possible to apply the treatment to the oil while in storage. In that event, oil may be continually pumped or otherwise recycled from the storage tank to a small treating chamber containing the treating element and then back to the tank. More advantageously, however, the treatment may take place in the tank itself. A number of the treating elements may be suspended in the oil to form a number of treating zones, and the oil may be recycled through sfich zones either by natural convection currents, if these are -sufficient, or by positive means for producing recycling currents. In that connection, it is to be noted that'the'term recycling is used herein broadly to include both positive and natural recycling. The means of recycling is clearly immaterial provided that recycling is actually achieved.

The action of the combination metals in the element according to the invention in combatting deterioration is not entirely understood. Oxygen itself is believed to have little harmful effect. lubricating oils is thought to be caused by the formation of hydroperoxides of hydrocarbons in the oil followed by a chain reaction involving free radicals. line with this, We have found that compounds which produee free radicals, such as benzoyl peroxide and ditertary butyl peroxide, increase the rate of deterioration of the-toils :markedly. We believe that the combination of the treating metals of the invention serve either to stablize the said hydroperoxide compounds or to decom- Oxidation of hydrocarbon The quantity of calcium combined in electrical contact with the sodium-solder alloy in the element according to the invention can vary within wide limits but preferably for practical reasons is chosen to be in such a quantity that in use its consumption parallels that of the sodiumsolder alloy so that both the sodium-solder alloy and the calcium of the element have approximately the same life so that upon exhaustion of the element no excess of either the sodium-solder alloy or of the calcium remains. Of course, other proportions are equally effective as long as some of both the sodium-solder alloy and calcium remain to provide the novel combination according to the invention.

The accompanying drawings illustrate by way of example a preferred mode of application of the invention. In such drawings, Fig. 1 shows a plug adapted to be aflixed in an oil container or circuit with its inner end in contact with the oil in the container or circuit and Fig. 2 shows a sectional view of such a plug when employed as the drain plug for the crankcase of an internal combustion engine.

Referring to the drawings, the plug according to the invention is composed of a threaded head 1 which carries a narrower threaded extension 2 which can be of steel. Elements 3 and 4, respectively, composed of a sodiumsolder alloy and calcium, are carried by threaded extension 2 which not only serves to hold such elements but also serves to ensure maintenance of the electrical contact between such elements when in use as in use the elements are consumed by erosion of the surfaces. As shown in Fig. 2, when such plug is used as a crankcase drain plug, it serves to close the drain opening in crankcase 5 of an internal combustion engine and in such position the inner end carrying elements 3 and 4 are maintained in continuous contact with the lubricating oil 6 circulating through the crankcase.

The treating elements according to the invention have an unexpectedly long life so that practically sized ele ments will remain effective for over a year when placed in the oil circuit of an internal combustion automobile engine. Their use not only efiectively reduces sludging and discoloration of lubricating oil or other hydrocarbon oils subject to deterioration during use or storage, but also efiectively prevents such oils from acquiring an acid reaction. The latter is most important in lubricating oils for internal combustion engines and use of the elements according to the invention so as to maintain the sodiumsolder alloy and calcium continuously in contact with the lubricating oil will reduce engine wear and therefore considerably extend the time before the engine will start .using oil and furthermore almost obviate the necessity of efiecting oil changes.

a The treating elements according to the invention have also been found useful when maintained in contact with hydrocarbon transformer oils, hydrocarbon fuel oils and hydrocarbon heat transfer oils.

The efiectiveness of the combination of the sodiumsolder alloy and calcium combination according to the invention is illustrated in the following examples which give the results of laboratory tests carried out under conditions where the oils involved are normally subject to rapid deterioration. In such tests the results obtained with applicants combination of a sodium-solder alloy (prepared by melting together 10% by weight of sodium with 90% by weight of a 50-50 Pb-Sn solder) in electrical contact with calcium are compared with results obtained with sodium-solder alloy and calcium separately and various controls. In such tests the 50 grams of various oils were heated to the temperatures indicated in an open 100 cc. Pyrex beaker in contact with the additions indicated. The quantity of sodium-solder alloy addition was about 1-1.5 grams, and the quantity of calcium was 0.1-0.2 gram. In those tests where copper and iron were also introduced into the oils in order that they also be in contact with the metals which, for example, may be pres- 4 A ent in lubricating systems or oil containers, the copper was in the form of a 50 mil copper wire 3.5 inches long and the iron was in the form of a 45 mil iron wire 5.5 inches long. The condition of the various oils was assessed by pH measurements. The pH determinations were made by taking 2 grams of the oil, admixing it with 10 cc. of neutral 50-50 benzene isopropyl alcohol mixture and determining the pH electrometrically.

Example 1 -In this test 50 grams of S. A. E.20 naphthenic lubricating oil containing no additives were used which originally exhibited a pH of 7.48. The heating was for 70 hours at 145 C. with the beakers left in an oven.

Sample addition: pH Blanksludged 3.70 Calcium-no sludge 4.75 Na-solder alloyno sludge 8.98 Na-solder alloy in contact with calciumno sludge 9.49

Example 2 In this test 50 grams of a lightly refined hydrocarbon oil, sometimes used in heat transfer work, which originally exhibited a pH of 7.03 was used. The heating was for 68 hours at C.

Sample addition: pH Blank 4.51 Calcium 6.38 Na-solder alloy 6.96 Calcium in contact with Na-solder alloy 7.81 Cu-i-Fe 4.32 Cu+Fe+Ca 4.91 Cu-i-Fe-l-Na-solder alloy 7.09 Cu+Fe+calcium+Na-solder alloy in contact 8.09

Example 3 In this test a highly refined paraffinic oil S. A. E. 20 having an original pH of 8.50 was heated for 46 hours at C.

Sample addition: pH Blank 3.69 Ca 3.92 Na-solder alloy 9.13 Ca-l-Na-solder alloy in contact 922 Example 4 In this test a lubricating oil for A. P. I. services MS DG having a viscosity of S. A. E. 10, having an original pH of 7.40, was heated for 137 hours at 160 C Example 5 In this test a non-additive lubricating oil having an original pH of 9.50 was heated at 160 C. for 40 and 137 hours respectively.

pH Sample Addition 40 137 hours hours Blank 7. 6S 4. 92 0a-- 8.15 6. 36 Na-solder alloy 8. 77 9. 21

Ca in contact with Na-solder alloy Example 6 In this test a highly refined parafiinic oil S. A. E. 20 lubricating oil exhibiting an original pH of 8.91 was heated for 46 hours at 160 C.

Sample addition: pH Blank 2.19

Ca 2.36 Na-solder alloy 8.01 Ca in contact with Na-solder alloy 8.86

Example 7 In this test a commercial parafiinic Pennsylvania type lubricating oil S. A. E. 20 exhibiting a pH of 8.14 was heated for 133 hours at 127 C.

Example 8 In this test a naphthenic oil used for making lubricating greases having an original pH of 9.16 was heated for 133 hours at 130 C.

Sample addition: pH Cu+Fe 4.89 Cu+Fe+Ca 4.54 Cu+Fe+Na-solder alloy 7.74 Cu+Fe+Ca+Na-solder alloy in contact 8.40

Example 9 In this test a heavy duty motor oil for A. P. I. services MM MS and DG S. A. E. 20 having an original pH of 8.49 was heated for 88 hours at 127 C.

Sample addition: pH Cu+Fe 6.59 Cu+Fe+Ca 6.82 Cu+Fe+Na-solder alloy 7.61 Cu+Fe+Ca+Na-solder alloy in contact 7.71

It will be seen that in each instance the oil containing the calcium-sodium-solder alloy combination according to the invention exhibited a higher pH after undergoing the heat treatment.

We claim:

1. A method for the continual treatment of a hydrocarbon oil to combat its continual tendency to deterioration which comprises continually recycling said oil through a treating zone in contact with fixed solid calcium and in contact with a fixed solid sodium-Pb-Sn solder alloy containing 2-15% by weight of sodium, said Pb-Sn solder containing 5-95% of lead and the remainder tin said calcium and sodium-Pb-Sn solder alloy being maintained in electrical contact in said treating zone.

2. A method for the continual treatment of a hydrocarbon oil to combat its continual tendency to deterioration which comprises continually recycling said oil through a treating zone in contact with fixed solid calcium and in contact with a fixed solid sodium-Pb-Sn solder alloy containing 510% by weight of sodium, said Pb-Sn solder containing 595% of lead and the remaindertin, said calcium and sodium-Pb-Sn solder alloy being maintained in electrical contact in said treating zone.

3. A method for the continual treatment of a hydro-' carbon lubricating oil circulating in a lubricating oil circuit of an internal combustion engine, to combat the continual tendency of said oil to deteriorate which comprises continually passing the oil in said circuit through a treating zone in contact with fixed solid calcium and in contact with a fixed solid sodium-Pb-Sn solder alloy containing 2-15% by weight of sodium, said Pb-Sn solder containing 5-95 of lead and the remainder tin during operation of said engine said calcium and sodium-Pb-Sn solder alloy being maintained in electrical contact in said treating zone.

4. A method for the continual treatment of a hydrocarbon lubricating oil circulating in a lubricating oil circuit of an internal combustion engine, to combat the continual tendency of said oil to deteriorate which comprises continually passing the oil in said circiut through a treating zone in contact with fixed solid calcium and in contact with a fixed solid sodium-Pb-Sn solder alloy containing 510% by weight of sodium, said Pb-Sn solder containing 5-95% of lead and the remainder tin during operation of said engine said calcium and sodium- Pb-Sn solder alloy being maintained in electrical contact in said treating zone.

5. A method for the continual treatment of a hydrocarbon lubricating oil circulating in the lubricating oil circuit of an internal combustion engine, to combat the continual tendency of said oil to deteriorate which comprises continually passing the oil in said circuit through a treating zone in contact with calcium and a sodium- Pb-Sn solder alloy containing 2-15% by weight of sodium, said Pb-Sn solder containing 5-95% of lead and the remainder tin in a fixed element comprising the calcium maintained in electrical contact with the sodium- Pb-Sn solder alloy during operation of said engine.

6. A method for the continual treatment of a hydrocarbon lubricating oil circulating in the lubricating oil circuit of an internal combustion engine, to combat the continual tendency of said oil to deteriorate which comprises continually passing the oil in said circuit through a treating zone in contact with calcium and a sodium-Pb- Sn solder alloy containing 5-10% by weight of sodium,

said Pb-Sn solder containing 5-9S% of lead and the remainder tin in a fixed element comprising the calcium maintained in electrical contact with the sodium-Pb-Sn solder alloy during operation of said engine.

7. An element for the treatment of hydrocarbon oil to lessen its tendency for deterioration comprising a supporting member carrying exposed calcium in electrical contact with an exposed sodium-Pb-Sn solder alloy containing 2-15 by weight of sodium, said Pb-Sn solder containing 595% of lead and the remainder tin, said supporting member being adapted to be positioned in an oil container with said calcium and sodium-Pb-Sn solder alloy in contact with the oil.

8. A crankcase drain plug carrying on its inner end a combination of exposed calcium in electrical contact with an exposed sodium-Pb-Sn solder alloy containing 2-15% by weight of sodium, said Pb-Sn solder containing 5-95 of lead and the remainder tin.

References Cited in the file of this patent UNITED STATES PATENTS 856,361 Neiburg June 11, 1907 1,865,235 Cross June 28, 1932 1,939,839 Williams et al Dec. 19, 1933 2,011,556 Hoge Aug. 13, 1935 

1. A METHOD FOR THE CONTINUAL TREATMENT OF A HYDROCARBON OIL TO COMBAT ITS CONTINUAL TENDENCY TO DETERIORATION WHICH COMPRISES CONTINUALLY RECYCLING SAID OIL THROUGH A TREATING ZONE IN CONTACT WITH FIXED SOLID CALCIUM AND IN CONTACT WITH A FIXED SOLID SODIUM-PB-SN SOLDER ALLOY CONTAINING 2-15% BY WEIGHT OF SODIUM, SAID PB-SN SOLDER 